Vaadin (http://vaadin.com/home) is an open source web application framework having a server-side architecture which constructs user interface of web applications as RIA (rich internet applications), using Java code only.

Vaadin Logo

For developing Vaadin applications, you only use Java code, like Java Swing. This Java code is then converted to GWT (Google Web Toolkit) components (which are HTML and Javascript based) for browser side, and AJAX code sections are generated for some actions to support RIA concept. Server side validation is also performed for all actions.

An example source code is shown below:

import com.vaadin.ui.*;

public class HelloWorld extends com.vaadin.Application {

public void init() {

Window main = new Window("Hello window");

setMainWindow(main);

main.addComponent(new Label("Hello World!"));

}

}

And the result is:

Vaadin Hello World Example

Vaadin supports so many UI components and these can be extended with new GWT components if required, and CSS themes can be applied to results. For using Vaadin, only a JAR file is enough. Some Eclipse and NetBeans plugins are also available for easier development if required.

But development time gain is very high and rich & interactive web components can be developed without any script language information. These parameters must be considered while choosing the technology.

Vaadin is very well documented. You can take a look at “Book of Vaadin”: